Stripping everything but alphanumeric chars from a string in Python

Question

What is the best way to strip all non alphanumeric characters from a string, using Python?

The solutions presented in the PHP variant of this question will probably

Answer 1

As a spin off from some other answers here, I offer a really simple and flexible way to define a set of characters that you want to limit a string's content to. In this case, I'm allowing alphanumerics PLUS dash and underscore. Just add or remove characters from my PERMITTED_CHARS as suits your use case.

PERMITTED_CHARS = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_-" 
someString = "".join(c for c in someString if c in PERMITTED_CHARS)